1. Field of the Invention
This invention generally relates to a memory storage apparatus for storing information on a memory medium, and, in particular, to a disk drive apparatus for storing information on a memory disk, such as an optical disk or magnetic disk.
2. Description of the Prior Art
A disk drive for storing information on a disk is well known in the art, for example, for use as an external memory of a computer system. Typical prior art disk drive apparatuses are schematically illustrated in FIG. 22 and FIGS. 23a and 23b. In these prior art disk drive apparatuses, a disk or a cartridge housing therein a disk is inserted into a tray of a loading unit 1 horizontally in the direction indicated by the arrow, and, as guided by a pair of L-shaped guide grooves 3 and 4, the tray 2 is first moved in the horizontal direction (disk insertion direction) to be located above a spindle motor, which is not shown, and, then, the tray 2 is moved downward in the vertical direction (perpendicular to the disk insertion direction), thereby causing the disk to be mounted on the spindle motor so as to be rotatably supported. In this type of disk drive apparatus, as shown in FIG. 22, when the disk is mounted on the spindle motor, which is not shown, a cone arm 5 is operated by a separately provided motor, thereby causing the cone arm 5 to pivot around a proximal end a thereof and a pressure cone 6 provided at the distal end of the cone arm 5 to hold the disk thus mounted on the spindle motor in
Moreover, in this type of the prior art disk drive apparatus, for example, as shown in FIG. 23a, it is so structured that a tension spring 7 is provided to bias the cone arm 5, which is pivotally supported at its proximal end a, to abut against the forward end b of the tray 1. And, as shown in FIG. 23b, when the tray 1 is moved downward to have the disk mounted on the spindle motor, the tray 1 is separated away from the cone arm 5 and the pressure cone 6 provided at the distal end of the cone arm 5 comes to hold the disk against the spindle motor under the force of the spring 7. However, in the case of the disk drive apparatus shown in FIG. 22, there is a problem of necessity to provide a separate motor. On the other hand, in the case of the disk drive apparatus shown in FIGS. 23a and 23b, since the distance 1 between points a and b is relatively short, the load applied to the tray 2 becomes large when the tray 2 is to be moved upward, and there is also a problem of incapability to utilize the movement of the tray 2 in the horizontal direction for vertical movement of the cone arm 5. Besides, in such a prior art structure, the stroke of movement of the pressure cone 5 is relatively large, so that this fact tends to hinder to make the entire disk drive apparatus compact in size.
Furthermore, in the prior art apparatus as shown in FIGS. 22 and 23, it is so structured that, after inserting a disk or a cartridge housing therein a disk into the tray 2 of the loading unit 2, an eject member mounted on the tray 2 is set in a latched condition so as to prevent the disk or cartridge from being undesirably ejected. Thereafter, the tray 2 is moved as guided by the L-shaped guide grooves 3 and 4. That is, in the first place, the tray 2 is moved horizontally to be located above a spindle motor, which is not shown, and then moved vertically downward to have the disk mounted on the spindle motor. In such a prior art structure, however, it is so structured that the cartridge becomes unlatched by its vertical downward movement, so that the cartridge tends to be ejected and thus encounters difficulty in entering into reference pins for positioning.
In addition, in a typical prior art disk drive apparatus as shown in FIG. 24, when a cartridge 1 housing therein a disk is inserted, an eject lever 3 biased by an eject spring 3 comes into engagement with a shutter provided on the cartridge 1, and as the cartridge 1 is further inserted, the eject lever 3 is pivotally moved clockwise under the force of the eject spring 2, whereby the shutter 4 in engagement with the tip end of the eject lever 3 is moved upward to open the cartridge 1. And, when the cartridge 1 has been completely inserted, the eject lever 3 is held in the position indicated by the one-dotted line by means of a latch mechanism (not shown) so that a head window of the cartridge 1 is opened, thereby allowing access to the disk housed in the cartridge 1 so as to carry out a reading and/or writing operation to the disk. Upon completion of such a reading and/or writing operation, the latch is released so that the cartridge 1 is ejected by the action of the eject lever 3 and the head window 5 of the cartridge 1 becomes closed by the shutter 4.
However, when the opening and closing operation of the shutter 4 and the ejection of the cartridge 1 are carried out by the single eject lever 3, the distance of ejection of the cartridge 1 by the eject lever 3 tends to be excessive so as to secure a sufficient opening and closing stroke of the shutter 4. If the biasing force of the eject spring 2 is lowered, then there is produced another problem of fluctuations in the ejection position of the cartridge 1.